Day 02

Peter Quint's Video Tutorials: Surface Shader I

Note from PQ: It's easier to build a shader from existing ones in material palette.

- The tutorial was done using Houdini9.5 which still had VEX/VOP operators which were used to build your own materials. Most of them are gone in Houdini11 as "Mantra Surface" Shader was added, most of the functions from the previous VEX/VOP were compiled into it.



Mantra Surface is energy-conserving, making it more physically correct just like mia_material from mentalray. In addition, Mantra Surface offers Subsurface Scattering (SSS) within it which mia_material does not.

Looking at shaders built by other artists on the forums, they consist of "surfaceModel" within their shop context. Same node found in Mantra Surface where you can find Diffuse, Specular, Reflection, Refraction, SSS, Index of Refraction (IOR), Fresnel and Bidirectional Scattering Distribution Function (BSDF).

Leaf Shader - http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=20988&highlight=shader

There was an explanation on micropolygons and the vectors in it such as s, t, normal vector, incident vector (believe to be the camera), L vector (Lightsource).






Also learnt about the output node at the end of every shader,
Cf = Colour
Of = Opacity
Af = Alpha
N = Normal
F = BSDF (used for Physical-Based Rendering, PBR)


Thought:

I want to build a water/liquid shader so it would be to start with surfaceModel node.
Definitely want diffuse, specular, reflection, refraction, SSS and IOR in my final shader.